Tourism poverty alleviation is an effective way to iron out the poverty problem in areas rich in tourism resources. Through field investigation and interview, this paper clarifies the current situation of tourism poverty alleviation in Zhongliao village, and summarizes the achievements of poverty alleviation. It was deemed that some residents had not really lifted themselves out of poverty. Then, based on the externality theory, this paper researches the external impact of local tourism poverty alleviation, and concludes that the development of tourism poverty alleviation not only helps to increase residents' income, raise living standards and improve living environment, but also increases the cost of social governance, causes traffic problems, and even lead to tragedy of the commons. Finally, in view of the existing problems, this paper offers proposals for the development of internalization of externalities. It is believed that a series of measures can be taken to reduce negative externalities from three aspects: government leading, economic regulation and public participation.